The present invention relates to plasma-treated textile surfaces for use in adsorptive filtering materials.
More particularly, the present invention relates to an adsorptive filtering material having protective function against chemical poisons, in particular chemical warfare agents and chemical noxiants, as classified and disclosed herein, in particular for the production of protective materials, such as protective suits, protective gloves, protective shoes, protective covers (for example to transport casualties) and the like, in particular for NBC deployment, and also to the aforementioned protective materials produced using this adsorptive filtering material.
There are a whole series of entities which are absorbed by the skin and lead to serious physical harm. Examples include the blister agent Hd (yellow cross) and the nerve gas sarin. People liable to come into contact with such poisons have to wear a suitable protective suit or be protected against these poisons by suitable protective materials.
There are in principle three types of protective suits: the air- and water-vapor-impervious protective suits which are equipped with a layer of rubber impervious to chemical poisons and which very rapidly lead to a build-up of heat; the air- and water-vapor-pervious protective suits which offer the highest wear comfort; and finally protective suits which are equipped with a membrane which allows water vapor but not the aforementioned poisons through. NBC protective clothing is thus traditionally produced either from completely impermeable systems (for example suits composed of butyl rubber) or permeable, adsorptive filtering systems based on activated carbon (in pulverulent, fibrous or spherulous form).
Protective suits against chemical warfare agents that are intended for prolonged use under a wide variety of conditions must not lead to a build-up of heat for the wearer. Air-pervious materials are therefore used in the main. The air-pervious, permeable protective suits generally possess an adsorbing layer comprising activated carbon which binds the chemical poisons very durably, so that even badly contaminated suits do not pose any danger to the wearer. The great advantage of this system is that the activated carbon is accessible on the inside as well as the outside, so that poisons which have succeeded in penetrating at damaged or otherwise unproof locations are very rapidly adsorbed. However, under extreme conditions, for example when a drop of a thickened poison impinges from a considerable height onto a somewhat open location on the outer material and is able to strike through to the activated carbon, the carbon layer may locally not be up to its task for a brief period.
The present invention therefore has for its object to provide an adsorptive filtering or protective material which at least substantially avoids the prior art disadvantages described above and which is especially useful for the production of NBC protective materials, such as protective suits, protective gloves, protective shoes, protective covers and the like.
This object is achieved in the realm of the present invention by an adsorptive filtering material as disclosed and claimed herein. Further, advantageous refinements of the adsorptive filtering material according to the preferred embodiment of the present invention are disclosed and claimed herein.
The present invention further provides for the use of the present invention's adsorptive filtering material for producing protective materials of any kind, in particular for producing protective suits, protective gloves, protective shoes and protective covers, preferably for NBC deployment, and also the thus produced protective materials of the aforementioned kind themselves.
According to a first aspect of the present invention there is accordingly provided an adsorptive filtering material which provides protection against chemical poisons, in particular chemical warfare agents and chemical noxiants, and has a preferably plural layered construction, the layered construction comprising at least one, in particular sheetlike (i.e. flat-shaped), supporting layer having two opposite sides and an adsorbing layer associated to the supporting layer and based on a material capable of adsorbing chemical poisons, wherein the surface of at least one of the two sides of the supporting layer is modified by plasma treatment.
This is because Applicant has found that, surprisingly, the properties, in particular the protective or adsorptive performance, of adsorptive filtering materials can be decisively influenced and improved when the supporting layer, which is customarily present in adsorptive filtering materials of this kind, is modified at its surfaces by means of plasma treatment. Plasma treatment provides a way of specifically adjusting the surface properties, such as surface constitution (for example roughness) and surface reactivities (for example hydrophilicity or hydrophobicity on the one hand or oleophilicity or oleophobicity on the other).
The fundamental idea of the present invention is thus to endow adsorptive filtering materials having a preferably plural layered construction with an enhanced protective function against chemical poisons, in particular chemical warfare agents and chemical noxiants, by the surface properties of the supporting materials, or supporting layers, customarily present in adsorptive filtering materials of this kind being modified by plasma treatment and thereby being appropriately adapted or optimized to the particular application requirements.
Further advantages, properties, aspects and features of the present invention will be apparent from the following description of preferred operative examples and as depicted in the drawings.